Sewing machine



Feb. 24, 1931,. L. M; scHo6 M KER ,5

SEWING MACHINE Filed pt. 15. 1924 2 SheetSPSheet' l awawwoz 40 was Feb; 24', 1931. L. M. SCHOONMAKER' 1,793,642

SEWING MACHINE I Filed Sept. 13,1924 2 Sheets-Sheet 2 mm-wm m avweuto'c Patented Feb. 24, 1931 PATENT" OFFICE LEON m. sonoomvmxnn, or FOREST HILLS, NEW Yon]:

SEWING MACHINE Application filed September 18, 1924. Serial No. 737,484.

The chief object of my invention is the provision of a truly portable electric sewing machine; that isto say, one of unusually small size and light weight, albeit an entirely practical machine capable of doing quite substantially the same work as the so-called portable electric sewing machines previously produced. Machines of my invention may be built small enough to be carried in a small satchelor a suitcase, and for operation preferably require only to be set on a table and plugged into a source of current, such as the conventional base outlet or a. lamp socket.

To the end indicated, the electric motor and the parts forming the sewing machine proper are built together as a single unit, in contradistinction to the usual practicewhich, in effect, is constructing substantially a complete sewing machine and applying thereto a motor constituting more or less a complete in-- dependent unit. The motor itself forms the base of the sewing machine as it were, the casing enclosing the electric motor mechanism forming the base of the entire device. This not only promotes compactness and light weight, but also produces a low center of gravity, which is especially important in small light machines.

It will be apparent however that the invention is also applicable to machines otherthan the very small size machines indicated.

Referring to the drawings, Figure 1 is a view in front elevation of a portable electric sewing machine embodying- Figure 6 is a horizontalsection on the-line VIVI.

In the illustrated embodiment of my invention, the part 1 is the sewing machine base, preferably cast with the customary upright standard 2 and its overhanging arm, and shown as split at 3, being reinforced by bolts 4, this base serving, in accordance with my invention, as a housing and support for the bearings 5 and 6 of a shaft 7. which carries the armature 8 of an electric motor, together with itscommutator 9, a fly wheel 10 and a spiral gear 11, the latter meshing with another spiral gear 12 upon the main driving shaft 13 of the sewing machine, these gears serving to actuate the rock-lever 14 and needle-bar 15 by means of a pitman 16 hooked at 17 to the rock-lever and connected at 18 with a crankpin on the gear 12. It will be observed that the electric motor mechanism is located immediately below the cloth plate 40, which is underneath the overhanging arm and between the plane (about at the plate 79) of the outer surface of the standard 2 and the plane of the needle .bar 15. The axis ofthe armature of the motor is substantially parallel to the overhanging arm.

The driving shaft 13 rotates in bearings 19 and 20 in the base 1, and actuates the rotating stitching mechanism 21, which may be of any suitable form to co-operate with the needle 22 in forming stitches, being illustrated as of a conventional type which does not require further description, and which is located between the planes of the top and the bottom of the motor mechanism as appears in Fig. 1.

A presser-foot is shown at 23, carried by a bar 24 mounted in the head 25 of the arm 2 and provided with a controlling handle 26, all of which may be of usual or suitable construction, as illustrated, the resser-foot co operating with a work-support 27 shown as a plate of substantially rectangular form preferably fast upon the part 28 of the base 1, being secured thereto by screws 29.

In accordance with an important feature of the invention I have shown at laminated magnet cores for the electric motor, having pole-pieces 31 upon which are wound the field coils 32, this field-magnet structure being built-in and supported by the sewing machine base, to minimize the bulk thereof, and for the same purpose I have illustrated commutator brushes 33 mounted in bearing sleeves 34 within insulating bushings 35 extendingthrough bosses 36 cast in the base 1, the brushes being held up to their work by springs 37, held adjustably in place by screws 38, the brushes being engaged with the commutator 9 and operating in usual fashion, but occupy ing a novel position in a sewing-machine base.

As a further provision for compact improved arrangement of the essential mechanisms in a unitary structure with the base 1, I prefer to include speed-changing devices controlled by movement of an essential part of the sewing-machine, and as the preferred arrangement for this purpose I have provided speed-changing devices comprising a resistance coil 39 operating in connection with the cloth-plate 40, which latter may be of any material and structure suitable to effect the above purpose. It is shown herein as a metal plate of generally rectangular shape secured by screws 41 upon a carriage 42 mounted to slide in ways 43 formed in the material of the base 1. This cloth-plate serves as part of the work-supporting structure, having an aperture 44 which registers with the worksupporting part 27 already described, and forms a movable extension thereof, in effect, and as one convenient form of speed-changing device I have shown a contact spring 45 (see Figure 4) secured by a screw or rivet 46 upon an insulating plate 47 secured by screws 48 to the under surface of the carriage 42.

To co-operate with this contact finger I have shown three contact studs or terminals 49 carried by an insulating block 50 secured by screws 51 upon the part 28 of the base 1, and conductors 53 are provided where needed to carry the electric current between the several parts of the motor and the speed-controlling mechanism, and also to a suitable source of current, such as a plug for use with the conventional wall or base receptacles, or with a lamp socket such as is found commonly in all modern buildings and which does not require illustration.

I prefer to provide means, such as a spring 54 held by an abutment 55 secured to the base 1 by a screw 56 and engaged with a portlon 57 of the insulating block 47, tending normally to press the cloth-plate 40 toward the operator to an extent which may be limited adjustably by the cap-screw 58. I prefer also to provide suitable means acting yleldlngly to maintain the cloth-plate 40 in any position of adjustment which may be desired, either with the motor at rest, or at a position corresponding to any selected one of the contacts formed between the member 45 and studs 49, and asone convenient form of such a device, I have shown a detent lever 60 carried by a screw 61 set in the base 1 in position to hold the detent 60 against the lower edge of the plate 40, in which are formed several notches 63, of which three are shown, corresponding to the three contact studs 49, and which represent three diiferent speeds of the motor.

In the position shown in Figure 3, the cloth-plate 40 is at its extreme outer position, toward the operator, corresponding to the position illustrated in Figure 4, where the contact finger 45 rests upon the insulating block 50, out of contact with any of the studs 49, so that the motor is at rest, and this position will be maintained by frictional engagement of the detent 60 with the under edge of the flange on the plate 40. When the operator presses inward on the plate 40 until the plate brings the first of the notches 63 opposite the detent 60, the latter will enter that notch and hold the cloth-plate yieldingly at a position in which the contact finger 45 is engaged with the first of the studs 49, completing the circuit through the motor for a relatively low speed, and if desired the operator can increase the speed by pressing the cloth-plate further inward with the work until the contact member 45 is engaged with the middle stud 49, or the third stud, and the detent 60 will rest in the corresponding notch 63, holding the cloth-plate 40 there until the operator again changes the position of the plate 40. The stud 61 is preferably provided with a tension spring 64, to aid in maintaining the detent in adjusted position.

To light the work, the arm 2 is preferably cast with an extension 70 to receive the socket 71 of an electric lamp 72, having preferably suitable means to turn the lamp on and off, such as the pull-chain 73. The extension may, and preferably will, be of suflicient length, parallel with the arm, to constitute a cylindrical member 74 having a window 75 through which the light of the lamp may illuminate the work-support 40 and the cloth thereupon. Preferably the inner surface of this cylindrical part will be formed of suitably concave shape to serve as a reflector, and I prefer to provide within this cylindrical casing 74 a protective shield 76 having an opening 77 which may be turned into position to register with the window 75, or may be turned around within the casing so that the shield 76 guards the lamp from injury. The shield 76 is preferably formed of reflective material to constitute the reflector proper.

I have shown the bottom of the base as provided with a protective sheet 78 of felt or other suitable material, and the numeral 79 designates a coverplate.

The part designated by the reference character 80 is the usual holder for the spool of thread 81, from which the thread 82 is led through the stationary post 83 to a take-up arm 84 on the lever 14, whence it passes around the tension device 85 mounted on a bracket 86, a leaf-spring 87 being shown, secured in place by a screw 88, which tends normally to press the bracket 86 against the a room having only a single lamp-socket.

The improved sewing machine can also be utilized by aseamstress, who is'enablednto carry the same upon field work, and start sewing at once upon arrival at the place of employment, and the machine is capable of any similar uses for which it is adaptable by the nature of the improvements above described, it being understood that certain of these improvements are susceptible of use individually in connection with sewing machines not corresponding in detail to the illustrated embodiment, and accordingly I do not limit myself to such details except so far as specifically set forth in the following claims:

I claim 1. The combination of sewing machine mechanism including the upright standard,

the arm extending therefrom, needle bar at the end of the arm and cloth plate underneath the arm, electric motor mechanism to drive the sewing mechanism, said electric motor mechanism being located immediately chine and between the plane of the outer surfaces of said standard and the plane of the needle bar, said planes being substantially at right angles to said arm, and a casing enclosing said electric motor mechanism, said cas-- ing forming the base of the entire device, and said upright standard risin from said casing.

In testimony whereof,

specification.

LEON M. SCHOONMAKER.

have signed this below the cloth plate and between the plane of the outer surface of said standard and the plane of the needle bar, said planes being substantially at right angles to said arm, and a casing enclosing said electric motor mechanism, said casing forming the base of the entire device, the brushes and bearings of the armature shaft of said electric motor mecha-. nism being carried by the walls of the casing, and said upright standard rising from said casing. a

2. The combination of sewing machine mechanism including the upright standard,

the arm extending therefrom, and needle bar at the end of the arm, electric motor mechanism to drive the sewing mechanism, said electric motor mechanism being located immediately below the cloth plate of the ma- 

